Continental Supergrid:Environmental Issues

Cradle to Grave Analysis

• new materials

• landscape placement

• O&M

• decommissioning

MgB2

The materials that go into making magnesium diboride, magnesium and boron, are both dirt-cheap. So cheap in fact that magnesium diboride cable may eventually be comparable in price with copper cable.

If it is going to be MgB2, let’s consider sources:

Magnesium

Currently world wide demand for magnesium exceeds supply. Demand is around 350,000 tonnes per annum while supply is about 304,000 tonnes annually.

The magnesium deposits which are currently being exploited, and the World’s main source of the element are found in Texas, Norway, Canada and Israel’s Dead Sea. Major deposits in Australia are found in Queensland and Tasmania.

We need to consider both sources and processing!

And SF6gets a bit closer to home:

Many things are beneficial in one setting and detrimental in another.  Such is the case with the compound sulfur hexafluoride (SF6).  Enclosed in electrical equipment, SF6 is an effective gaseous dielectric that allows for the safe transmission and distribution of electricity. Yet, when SF6 is released to the atmosphere, it is a highly persistent greenhouse gas that contributes to global climate change.  It is the second characteristic that has prompted the EPA to work with electric power providers to launch the voluntary SF6 Emissions Reduction Partnership for Electric Power Systems.

Boron

Locations where boron production and processing are likely to influence the environment

The message is simply that the production and processing of source materials can have unwanted environmental consequences (direct and indirect).

If the supergrid expands the market for these materials, then we can expect environmental effects!

And!

“second-generation high-temperature superconductor, a compound of yttrium, barium, copper, and oxygen, which is in the early stages of development.”

What I found on MgB2 production was limited, but the laboratory production is informative:

Xiaoxing Xi of Pennsylvania State University and his colleagues heated chips of magnesium to more than 700 degrees Celsius in the presence of hydrogen gas. When they added diborane gas (a mixture of boron and hydrogen), a film of MgB2 began to grow on a sapphire

surface within the reaction chamber.

I conclude that production of MgB2 may be less complicated that making the computer chips supporting this presentation.

The manufacture of MgB2 seems pretty innocuous. First you have to make a powder and then form it into a wire.

There will undoubtedly be environmental and health issues in this processing, but the technologies used appear to be mature and controllable.

So to this stage of my analysis I see no smoking “environmental” gun, but we need to remember that there can be secondary effects.

The next stage of the process considers how our superconducting cables will be used.

The supergrid will build new power plants, and trench, tunnel, or dig it’s way across the landscape.

The environmental consequences of production are well defined. We also have a pretty good sense of the environmental effects of transmission facilities.

The major environmental concern I have is the landscape disruption associated with construction, and the secondary effects associated with growth from, in, or around the grid.

We are just beginning to recognize the need for smart growth, and how to achieve low impact development. The supergrid provides us with a chance to rethink the paradigm recognizing that the supergrid will attract growth, and we have an opportunity at this stage of the planning to consider how that growth can be managed.

Paul Grant’s vision of a future city examines the infrastructure issues well, but we need to consider additional environmental issues from a landscape perspective.

A landscape perspective is based on a recognition of scale differences, and a careful consideration of environmental issues at different scales.

Landscape ecology is providing that perspective. We are developing the capacity to address environmental issues at the scales appropriate to the supergrid.

In landscape ecology, patches are spatial units at the landscape scale. Patches are areas surrounded by matrix, and may be connected by corridors.

Corridors are elongated patches that connect other patches together. Three major types of corridors are:

•line •strip •stream

What is important to consider in the supergrid is that the nodes will be loci of effect expansion, and the grid, acting as a corridor, will both connect and isolate landscapes.

In a practical sense too, we need to consider the environmental consequence of such a major effort at linkage. Fiberoptic cables were installed often using existing railroad corridors. Will the supergrid use existing corridors or require new ones?

Each option will have a unique set of environmental issues.

Finally to decommissioning!

• environmental remediation

• equipment dismantling

• building demolition

• land “reclamation”

From Weston Environmental Services:

There is a clear need to decommission supergrid facilities, but what about existing facilities that the supergrid will make obsolete?

Using a UK Department of Trade and Industry report on Energy, I found some interesting statistics on UK oil rigs. Granted we can leave some in place for habitat, but decommissioning will be a major issue.

Summary:

The Continental Supergrid will require new assessment procedures that effectively address cradle to grave considerations over large spatial and long temporal scales. To meet the environmental assessment needs, we will need a technology development process for environmental effect/impact analysis that is as advanced as the scientific and engineering supporting the supergrid.

The challenge to our discussions is to consider environmental issues at the earliest stages of supergrid system development. Further, it is important that environmental issues drive an adaptive approach to technology development. Adaptive in the sense that early and complete environmental issue analysis can be expected to produce changes in technology, technology applications, and systems operation and configuration.

y

y

y

y